Stride Marching Cubes Voxel Terrain

Procedural voxel terrain for Stride, meshed on the GPU with a Marching Cubes compute shader. Fill chunks with one of three built-in noise generators, mesh them with smooth gradient normals, and shade the surface with a per-triangle multi-material colour blend — no textures required.

What's in the box

File	Role
VoxelTerrain	Drop-in SyncScript. Builds a finite chunked map, spread over a few frames. Pick a generator + size in Game Studio.
MarchingCubesMesher	The GPU mesher: uploads a VoxelGrid, dispatches the compute shader, returns a ready-to-render MCVertex buffer.
VoxelGrid	Packed chunk storage (density + material per voxel). Sampled from world coords so chunks are seamless.
TerrainGenerators	ITerrainGenerator + Perlin, Ridged, Caves3D — each parameterised (height, amplitude, frequency, octaves).
Noise	A small, dependency-free Perlin/FBM/ridged noise.
TerrainPalette	Per-material colours, uploaded as a tiny palette texture. Reskin the terrain by editing it.
TerrainType / MCVertex	The material enum and the 28-byte GPU vertex (Position, Normal, PackedMaterial).
Effects/GenerateMarchingCube.sdsl	The Marching Cubes compute shader (gradient normals, surface-material scan, reversed winding).
Effects/TerrainDiffuse.sdsl	Multi-material surface shader: blends the dominant + secondary palette colour per triangle.

Quick start (drop-in)

1. Reference StrideMarchingCubeSystem from your game project.
2. Add an empty entity, attach a VoxelTerrain component (category Terrain).
3. Choose a Generator (Perlin / Ridged / Caves3D), map size and noise settings.
4. Press play — the map builds itself.

Use it directly (your own world)

var gen = TerrainGeneratorBase.Create(NoiseKind.Ridged, seed: 1337,
    baseHeight: 24, amplitude: 40, frequency: 0.015f, octaves: 5);

using var mesher = new MarchingCubesMesher(Services, GraphicsDevice);
var grid = new VoxelGrid(32);
gen.Fill(grid, worldX0, worldY0, worldZ0);          // sample from absolute world coords

var mesh = mesher.GenerateMesh(grid, (Game)Game, isolevel: 0.5f);
if (mesh is var (vbo, count) && count > 0)
{
    // build a Mesh with MCVertex.Layout over `vbo` (DrawCount = count), assign your terrain material…
}

Write your own generator by implementing ITerrainGenerator (or subclassing TerrainGeneratorBase and overriding SurfaceHeight / Carve), and set the per-voxel TerrainType however you like — the shader resolves the dominant + secondary material per surface triangle and blends their palette colours.

How it works

• Voxels → surface on the GPU. VoxelGrid packs density (bits 0-7, 0 = solid, 255 = air) and material (bits 8-15) into one ushort per voxel — exactly the GPU layout. The compute shader marches each cube, interpolates edge vertices, derives a smooth normal from the density gradient, and appends triangles via an atomic counter.
• Seamless chunks, no stitching. Every sample (including the Size+1 border row) is computed from absolute world coordinates, so neighbouring chunks share identical boundary values and line up exactly.
• Multi-material. For each surface triangle the shader scans its active edges at full voxel resolution to find the real surface material, picks a dominant + secondary material, and packs them (plus a blend weight) into the vertex. TerrainDiffuse blends the two palette colours — so slopes fade grass→rock, beaches fade sand→grass, etc.
• Three generators. Perlin (rolling hills), Ridged (mountains), Caves3D (hills carved by 3D noise into caves and overhangs). All share the height/depth material banding.

Demo

Open StrideMarchingCubeSystem.sln, set Demo.Windows as startup and run. A 192×64×192 map builds over a few frames; fly around with WASD + right-mouse. Change the VoxelTerrain component's Generator/Seed/Amplitude in Game Studio to reshape the world.

License

MIT. See LICENSE.md.